python - Python无法连接到grpc channel ->“无法连接到所有地址”“grpc_status”:14

尝试调用存根方法时出现以下错误。
知道是什么原因造成的吗？

[bolt.api.handlers] 2019-08-21 20:07:57,792 ERROR handlers:1066: 'ResourceHandler' object has no attribute 'ontology_service_handler'
Traceback (most recent call last):
  File "/bolt-webserver/bolt/api/onse/onse_handlers/ontology_service.py", line 17, in post
    ontology_id = await self.onse_stub.createOntology()
  File "/bolt-webserver/bolt/api/onse/onse_stub.py", line 41, in createOntology
    return self.stub.CreateOntology(ontology_messages_pb2.Ontology())
  File "/usr/local/lib/python3.6/site-packages/grpc/_channel.py", line 565, in __call__
    return _end_unary_response_blocking(state, call, False, None)
  File "/usr/local/lib/python3.6/site-packages/grpc/_channel.py", line 467, in _end_unary_response_blocking
    raise _Rendezvous(state, None, None, deadline)
grpc._channel._Rendezvous: <_Rendezvous of RPC that terminated with:
        status = StatusCode.UNAVAILABLE
        details = "failed to connect to all addresses"
        debug_error_string = "{"created":"@1566418077.791002345","description":"Failed to pick subchannel","file":"src/core/ext/filters/client_channel/client_channel.cc","file_line":3818,"referenced_errors":[{"created":"@1566418077.790965749","description":"failed to connect to all addresses","file":"src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc","file_line":395,"grpc_status":14}]}"

我试图提供IP地址而不是主机名，但是仍然出现相同的错误。 OnseStub类在调用createOntology方法之前就已初始化。
服务已启动并正在运行。
失败的通话是通过龙卷风Web应用程序完成的（如果可能的话）

class OnseStub:

    def __init__(self, ontology_service_backend):
    self.channel = grpc.insecure_channel('localhost:51051')
    self.stub = ontology_service_pb2_grpc.OntologyServiceStub(self.channel)

    def __del__(self):
    if self.channel != None:
    self.channel.close() # close grpc channel

    async def createOntology(self):
    return self.stub.CreateOntology(ontology_messages_pb2.Ontology())

最佳答案

这是常见错误，它可能在不同情况下发生。但是在大多数情况下
可以通过未设置http_proxy环境变量来修复https://github.com/grpc/grpc/issues/9987

if os.environ.get('https_proxy'):
 del os.environ['https_proxy']
if os.environ.get('http_proxy'):
 del os.environ['http_proxy']